In a computing environment, a markup language can be used by an author to create a document that is displayed based at least in part on text provided in the document and accompanying annotations that generally describe how the text is to be displayed. For example, text characters may be included in the document, along with annotations comprising formatting instructions, presentation instructions, procedural instructions, and/or descriptive markings. In this example, the text and annotations can be used to create a viewable or processable version of the document, which may comprise text, images, media, links, and other viewable components. Markup language can be used for a variety of document types, such as in word processing documents (e.g., using a presentational markup), macro or subroutine documents (e.g., using procedural markup), and web-based documents (e.g., using descriptive markup).